The 770 Grosser, or W07 as it was code-named, received a major revision in 1938, switching to a new 150W label.
The car received all-around improvements having seen the introduction a new oval section tubes chassis and a new suspension system. The older semi-elliptical leaf-spring/solid axle configuration was discarded in favor of a coil-spring layout with front independent suspension and rear de Dion axle. The older W07 engine was upgraded to produce mode power and the transmission received an extra ratio. The W150 was one rare build as well, having been produced in just 88 units throughout its production time.